Azo dyes and methods for their preparation



Patented Sept. 10, 1935 UNITE AZO DYES AND METHODS FOR THEIR PREPARATION No Drawing. Application July 27, 1933, Serial No. 682,429

8 Claims.

This invention relates to the manufacture of azo dyes, and more particularly refers to the production of insoluble azo dyes having the following general formula:

OH CONH in which X represents an alkyl or alkoxy group.

Heretofore in producing orange shades on textile material halogenated amino-benzenes were diazotized and coupled on the fibers with arylamides of 2,3-hydroXy-naphthoic acid. This widely used method was subject to the great disadvantage that the shades produced were dependent to a great extent upon the subsequent soaping operation, and as a result uniformity of shade was almost impossible of attainment. It is well known that when the dye was first produced on the textile material the resulting color was scarlet. The dyed material was then carefully subjected to a rigid soaping treatment, which changed the shade from scarlet to a bright orange. Due to unavoidable variations in even the most careful soaping treatment, the resulting orange shades varied considerably and could not be reproduced with any satisfactory degree of accuracy.

Because of the aforementioned difficulty it became customary in commercial dyeing practice to utilize a mixture of yellow and scarlet dyes when orange shades were desired. Such a mix ture permitted the commercial dyer to obtain the particular degree of orange which he desired and to reproduce this shade when necessary. However, the mixed colors imparted thereby were greatly inferior in fastness to light, laundering and chlorine to colors produced by the use of a single dye.

Quite recently the one-bath process of dyeing has gained wide popularity, due to its ease of application and satisfactory results. This process, as is Well known, comprises briefly the production of soluble diazoimino compounds, derived from the diazo components and certain soluble stabilizing agents. The diazoimino compounds are mixed with arylamides of 2-3-hydroxy-nap'hthoic acid and suitable assistants. Textile material is then printed with the paste formed therefrom,

and the color developed thereon by treatment with dilute acids at elevated temperatures. Since this color development depends upon hydrolysis of the diazoimino compounds resulting in regeneration of the parent diazo salts which then couple with the arylamides present in the printing paste, it is essential that the diazoimino compounds be readily hydrolyzed when treated with the aforementioned hydrolyzing agents. Diazoimino compounds prepared from halogenated am- 10 ino-benzenes have been found to be unusually stable, hence prints obtained from mixtures of such diazoimino compounds and the arylamides are unusually resistant to the action of heat and acids. Due to the stability of these diazoimino 15 compounds color development is necessarily slow and unsatisfactory.

It has now been found that the aforementioned difliculties may be avoided, and attractive orange shades imparted to textile material by the use of new azo dyes which will be more fully described hereinafter. These shades have exceptional uniformity and fastne'ss. Furthermore, the soaping treatment does not have such a marked efiect on the resultant shade, consequently the desired shade may be reproduced without difficulty. Likewise, diazoimino compounds produced from the diazo salts described herein and suitable stabilizing agents are readily hydrolyzed when subjected to treatment with dilute acids at elevated temperatures.

It is an object of this invention to produce new insoluble azo dyes and pigments. A further object is to produce azo dyes which impart attractive orange shades of excellent uniformity to textile material. A still further object is to produce l dyes which are not dependent upon rigidly controlled soaping treatments for their resulting shades. An additional object is to produce com- 40 pounds which hydrolyze readily and are well adapted for use in one-bath dyeing processes. Additional objects will become apparent from a consideration of the following description.

. These objects are attained according to the herein described invention which comprises coupling diazotized aniline with an ortho-alkylor orthoall oxy-substituted anilide of 2-3-hydroxynaphthoic acid, preferably an orthomethyl,

-ethy1-, -methoxy, or -ethoxy-anilide of 2-3- hydroxynaphthoic acid.

The invention may be more readily understood by a consideration of the following illustrative examples, in which the quantities are stated in parts by weight:

Example 1 28 parts of aniline were stirred with '76 parts of hydrochloric acid of 37% strength, the mass cooled, and about 150 parts of ice added to adjust the temperature to 0-2 C. 21 parts of sodium nitrite were dissolved in 100 parts of water, and added slowly to the above solution of aniline-hydrochloride, maintaining the temperature in the above range.

When diazotization was complete, the clear diazo solution was slowly added, with stirring, to a solution of 43 parts of piperidine-alpha-carboxylic acid dissolved in 400 parts of water, to which had been added sufiicient sodium carbonate to render the solution alkaline to phenolphthalein papers. The temperature was held at 5 C. during the addition of the diazo solution, and sodium carbonate added as required to maintain alkalinity to phenolphthalein.

When coupling to the diazoimino compound was completed, the solution was heated to 40 C. and filtered to remove small quantities of insoluble matter. Enough sodium chloride (of C. P. quality) was then added to produce a salt concentration of 15% in the filtrate. The diazoimino compound precipitated as an oil, was separated, and dried in a vacuum at 65 C. After drying, the product was a tan solid, which was very soluble in water, stable toward cold alkalies, but rapidly hydrolyzed by the action of weak acids, particularly at elevated temperatures. Approximately 68 parts of the product were obtained.

2.7 parts of the diazoimino compound obtained as above, whose probable formula is:

were mixed and finely ground with 2.3 parts of the ortho-toluidide of 2-3-hydroxy-naphthoic acid. A printing paste was then prepared according to the following formula:

5.0 parts of the dry mixture of diazoimino compound and arylamide 2'7. 0 parts water 3.0 parts sodium hydroxide solution of 35% strength 65. 0 parts starch-tragacanth thickener of the following composition:

parts wheat starch 360 parts gum tragacanth 6% solution 560 parts water Cotton piece goods were printed from an engraved roll with the above paste, the prints dried in the air, and then subjected to the action of live steam containing the vapors of acetic acid.

,Rapid color development took place-the time for complete development was: very much less than is required for similar development when the diazoimino compounds obtained by the action of diazotized meta-chloroaniline or 2,5-dichloroaniline upon piperidine-alpha-carboxylic acid were substituted for the aniline derivative in the above process.

When color development was complete, the printed goods were rinsed with water, boiled for 5 minutes in a 0.5% soap solution, again rinsed, and dried. Before soaping, the printed pattern on 0 ONE? Ha Example 2 2.7 parts of the diazoimino compound of Formula (A) were mixed and ground with 2.3 parts of the ortho-phenetidide of 2-3-hydroxy-naphthoic acid. A printing paste Was then prepared according to the following formula:

Parts Dry mixture of diazoimino compound and coupling component 5 Water 27 Sodium hydrox de solution of 35% strength- 3 Starch-tragacanth thickener 65 Cotton piece goods were printed with the above paste, then immersed in a boiling saturated sodium chloride solution, to which had been added a small quantity of acetic acid. The printed pattern was developed as a reddish-orange. The printed goods were then rinsed, soaped at the boil, again rinsed and dried. The pattern then appeared as a bright orange dyeing, due to the formation of the new dye of the probable formula:

0 more? As compared with a similar dyeing prepared,

utilizing a mixture of the piperidine-alpha-carboxylic acid diazoimino derivative of m-chloroaniline with the o-toluidide of 2-3-hydroxynaphthoic acid the color was yellower and brighter in shade and clearer in tone. The dyeing exhibited superior fastness to laundering and chlozinc, and somewhat inferior fastness to light. Color development Was very much more rapid when the new composition was used and the new color produced.

Example 3 28 parts of aniline were diazotized as described in Example 1. The clear diazo solution was then added slowly and with stirring to a solution of 60 parts of methyl-glucamine in 600 parts of water, to which sufficient sodium carbonate had been added to render the mass alkaline to phenolphthalein papers. The temperature was held at 5 C. during the coupling, and sodium carbonate was added as required to maintain the phenolphthalein alkalinity.

When formation of the diazoimino compound was complete, the solution was heated to 40 C. and filtered to remove small quantities of insoluble matter. Pure sodium chloride was added to the filtrate in a quantity suiiiclent to produce a 15% concentration of the salting agent. The new diazoimino compound, of the probable formula:

separated as a light yellow solid. It was filtered, washed with a little ice water, and dried at 55 C. About 127 parts of product were obtained containing about 60% of the diazoimino compound and 40% of inorganic salts.

3.3 parts of the diazoimino compound obtained as above were mixed and ground with 1.7 parts of the ortho-ethyl-anilide of 2-3-hydroxy-naphthoic acid. A printing paste was then prepared according to the following formula:

Parts The above dry mixture of diazoimino compound and arylamide Water 27 Sodium hydroxide solution of 35% strength- 3 Starch-tragacanth thickener 65 Cotton piece goods were printed with the above paste, dried in the air, and then subjected to the action of live steam containing the vapors Rapid color development resulted, and the printed pattern was developed as a reddish-orange dyeing. The printed goods were rinsed, soaped at the boil, again rinsed and dried. The pattern then appeared as a bright orange dyeing of good fastness, due to the formation of the new dye of the probable formula:

QN=IF CONH- CgHE Example 4 Cotton piece goods were padded in the usual manner with the o-anisidide of 2-3-hydroxynaphthoic acid, then immersed in a solution of diazotized aniline prepared as described in Example 1, but to which enough sodium acetate had been added to neutralize the mineral acidity. When color development was complete, the goods were rinsed, soaped at the boil, again rinsed, and dried. The textile fabric was dyed to a bright orange of good fastness, due to the formation of the new dye of the probable formula:

CONH

OCH:

It is understood that the processes untilized in the aforementioned examples are merely illustrative of the present invention, and may be subjected to considerable variation and modification.

For example, the arylamide of 2,3-hydroxynaphthoic acid need not be an ortho-toluidide-. ortho-phenetidide-, ortho-ethyl anilideor or tho-anisidide of 2,3-hydroxy-naphthoic acid. Other alkyl or alkoxy groups may be substituted thereon in place of the aforementioned substituents. However, it is to be understood that the results obtained by using the aforementioned arylamides are preferred, and are in general superior to results obtained by using the remaining alkyl or alkoxy derivatives which come with in the scope of this invention.

The colors comprised herein may be imparted to the fibers by means of well known dyeing processes. Among these processes the following may be mentioned:

(1) The fibers may be padded with the arylamides described herein, and then immersed in a solution of diazotized aniline.

(2) The fibers may be impregnated with the arylamide and printed with pastes containing diazotized aniline.

(3) Aniline may be converted to its anti-diazotate (nitrosamine) and the fibers printed with pastes comprising the anti-diazotate and an arylamide. The printed fibers are then subjected to treatment with mild acids, preferably at elevated temperatures.

(4) Aniline may be diazotized and reacted with various aliphatic, isocyclic and heterocyclic amines, preferably containing water-solubilizing groups, resulting in the formation of diazoimino derivatives. Textile material may be printed with the pastes comprising such diazoimino derivatives and the arylamides referred to herein. The printed fibers may then be subjected to the action of mild acids at elevated temperatures.

In utilizing the one-bath process numerous diazoimino derivatives of aniline may be selected. Among the stabilizing agents which may be substituted for piperidine-alpha-carboxylic acid and methyl-glucamine, referred to in the above examples, mention may be made of the following:

Sal-cosine Ethyl-taurine Proline Dlethanolamine NHl 4-sulfo-2-amino-benzoic The stability of the diazoimino compounds produced by the action of diazotized aniline on various stabilizing agents, a few of which have been referred to previously, will necessarily vary. Consequently, the rate of color development when fibers are impregnated with pastes containing such diazoimino compounds and arylamides Will depend to some extent upon the diazoimino compound selected. However, it has been found that such color development is much more rapid than that obtained from mixtures containing the corresponding diazoimino derivatives of the halogenated anilines as coupling components.

The results obtained herein are quite surprising, since it has been generally conceded that the production of orange shades required the use of negatively substituted diazotized arylamines. As a result of the experimental work disclosed herein, it has been found that orange shades may be obtained by the use of a diazotizecl arylamine entirely free from negative components. This invention is furthermore surprising in that the resulting colors are not only orange but are often greatly superior to those colors produced by the use of negatively substituted arylamines. This is a revolutionary departure from the prior art and completely refutes the universal idea that negative components were essential in this connection.

The instant invention permits the production of attractive colors having exceptional uniformity. These colors are fast to light, washing and chlorine, and may be readily imparted to textile materials. The compounds disclosed herein hydrolyze readily and are well suited for use in oneba-th dyeing processes. They eliminate the necessity of using mixtures of yellow and scarlet dyes in order to obtain desirable orange shades, with the additional expense incurred thereby. Furthermore, the shades are greatly superior to those obtained according to the prior art. Due to the low cost of the components utilized herein, as well as the superior results and ease of application, the processes heretofore described should result in completely revising the methods now in use for imparting orange colors to textile materials.

As many apparently Widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as delined in the appended claims.

I claim:

1. A process for producing insoluble azo dyes which comprises coupling diazo-tized aniline with a member selected from the group consisting of ortho-alkyland ortho-alkoxy-substituted anilides of 2,3-hydroxy-naphthoic acid.

2. A process for producing insoluble azo dyes which comprises coupling diazotized aniline with the o-toluidide of 2,3-hydroxy-naphthoic acid.

3. A process for producing insoluble azo dyes which comprises coupling diazotized aniline with the o-phenetidide of 2,3-hydroxy-naphthoic acid.

4. A process for producing insoluble azo dyes which comprises coupling diazotized aniline with the o-ethyl-anilide of 2,3-hydroxy-naphthoic acid.

5. Insoluble azo dyes having the following gen- 5 eral formula:

wherein R represents a coupling component selected from the group consisting of ortho-alkyland ortho-alkoxy-substituted anilides of 2-3-hydroxy-naphthoic acid.

6. An insoluble azo dye having the following formula:

o ONHO which imparts a bright orange shade to cotton.

' 7. An insoluble azo dye having the following formula:

OH 0 ONE? which imparts a bright orange shade to cotton.

8. An insoluble azo dye having the following formula:

C ONE which imparts a bright orange shade to cotton.

FRITHJ OF ZWILGMEYER. 

